Hangover impairs judgment in young adults

NEW YORK (Reuters Health) - It's not enough to "sleep it off" after a night of drinking.

According to a study released today, the effects of intoxication last long after the booze is out of the blood, not only leaving a nasty hangover but also slowing reaction times and the ability to concentrate the next morning.

Rhode Island and Massachusetts researchers found that it didn't matter whether the liquor consumed was clear or dark; the level of brain impairment was the same the next morning.

"People will be impaired the morning after - after the alcohol leaves the system," Dr. Damaris Rohsenow of the Brown University Center for Alcohol and Addiction Studies in Providence, Rhode Island noted in a telephone interview with Reuters Health.

The findings are based on a study looking at the effects of heavy drinking on 95 young adults between the ages of 21 and 33. The subjects spent two nights at the Boston test facility. One night they were given alcohol (either vodka or bourbon mixed in cola) and the other night they were given a placebo. The researchers determined their blood alcohol levels, sleep patterns and ability to think quickly and over a long period of time.

To approximate the effects of drinking on an empty stomach, Rohsenow and colleagues gave test subjects a standardized meal three hours before the test liquids were given until subjects reached a minimum blood alcohol level of 0.09 grams percent. (In all 50 states, 0.08 grams percent is considered legally drunk.)

Previous research shows that symptoms of a hangover (headache, nausea, sleepiness) usually lift within a few hours of waking. While this study did not measure how long impairment lasted, Rohsenow told Reuters Health: "It's likely that the performance effects probably lift within a few hours," too.

Vodka and bourbon appear on each extreme of alcohol purity: vodka is the most free of impurities while bourbon has the highest level - all other alcohols are somewhere in between.

Previous research shows that the higher the impurities the lousier a drinker is likely to feel the next day, but this study showed that impairment was the same.

"Bourbon versus vodka didn't make a difference; the biggest thing was the alcohol itself," Rohsenow said.

Subjects given alcohol the night before "thought their ability to drive a car was as good as or better" than those who were administered placebo, Rohsenow said.

It "might be a good rule of thumb (to) wait until they don't feel so lousy the next morning before doing any activities that might involve operating dangerous equipment," Rohsenow said.

The researchers chose to study young adults because there are more heavy drinkers among this age group, it's safer, and they have more time to devote to the overnight stays required by the study. As a result, the findings can only be applied to people between the ages of 21 and 33.